This is a proposal to study the social and political context of health screening for genetic diseases. Genetic screening is distinguished from all previous forms of health screening because of the unique relationship between ethnic and racial boundaries of many genetic diseases and the social stratification of ethnic and racial groups. Thus, for the first time in American history, social policy has deliberately and consciously intervened in the biological destiny of socially identified aggregates, with scientific legislation. A research team of four professionals with inter-disciplinary concerns will compare and contrast the social histories of five diseases (Tay-Sachs for Jews; Sickle-Cell Disease for Blacks; Thalassemia for Mediterraneans, especially Italians; Down Syndrome, which is thought to be age-related, and Hemophilia, which is sex-linked), in order to sharpen the social and political explanations for different strategies of treatment and different patterns of mobilization for, and against, genetic screening. We plan to work at four levels of inquiry: the national or federal level, with an account of legislative history; the regional, state, and broader institutional level, with studies of two state administrations of public health and state legislative policy; at the clinic level, studying the doctor/patient relationship and the clinic organization and structure; and the family/community context of genetic disease. Methods include document analysis, comparative historical and cross-sectional comparative analysis, interviews with stratified samples of those screened and their families, and interviews with state health administrators, lobbyists, legislators, and more locally, clinic staff. The explicit policy for data analysis and interpretation is to contextualize and integrate four levels of inquiry by tracing the links (or disjunctions) between levels, while comparing, horizontally, the social frame of each of the five different diseases.